1. Field of the Invention
The present invention relates to measuring the interfacial tension of a hydrocarbon liquid. The amount of interfacial tension is generally related to the amount of surfactants in the liquid. The amount of surfactants may affect the coalescing operation used to remove water from the liquid.
2. Description of the Prior Art
The necessity of removing water from fuels, such as JP4 or JP5 jet fuel, and the attendant dangerous icing conditions at high altitudes, is obvious. Water in diesel fuel can also be destructive to diesel engines during normal operations over a wide variety of operating temperatures.
It has been common to pass liquids, such as jet fuel or diesel fuel, through a coalescing operation using a coalescing filter at various times before use, such as during transfer from an underground storage tank to a tanker truck. Sometimes a coalescing filter is provided at the nozzle of the hose from the tanker truck to filter the fuel immediately before delivery into the fuel tank of the aircraft.
Presence of surfactants in the fuel being treated adversely affects the efficiency of the known filter coalescing elements and may render the element unable to remove the desired water content to produce clean dry fuel.
Accordingly, those experienced in the prior art have continually searched for a quick and easy way to determine the presence of surfactants in liquids.